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In-Situ Testing & Geophysics

Shear Wave Velocity & Vs30 from SPT / CPT

Estimate the Vs profile and Vs30 from SPT (Imai & Tonouchi, Ohta & Goto) or CPT (Robertson, Mayne), with ASCE 7-16/22, NBCC and Eurocode 8 site classes.

Imai & Tonouchi (1982)Ohta & Goto (1978)Robertson (2009)ASCE 7-22

Inputs

Demo

1. Test Data

Depth (m)SPT NSoil (Ohta & Goto)

Enter N60 (or N for the energy of Japanese practice, about 70%). The SPT correction tool converts field N to N60.

Results

Enter SPT blow counts or paste a CPT sounding above, or click a Demo preset, to estimate the shear wave velocity profile and Vs30.

Theory and formulae

Shear Wave Velocity Correlations

About this calculator

This free shear wave velocity (vs30) calculator runs entirely in your browser: what you enter is never uploaded. Use the calculation steps and the theory section to check the working, and print a calculation sheet with the inputs, results and formulae for your records.

Methods and references: Imai & Tonouchi (1982), Ohta & Goto (1978), Robertson (2009), ASCE 7-22.

Topics: shear wave velocity, vs30, vs from spt, vs from cpt, imai tonouchi, ohta goto, robertson, site class, nbcc, asce 7-22, seismic.

Engineering notice: Results are for preliminary estimation, screening and education. All inputs and outputs must be independently verified by a qualified professional engineer before use in any design or construction decision. Read the full disclaimer